/* ============================================
   Variables & Base Styles
   ============================================ */
:root {
  --color-primary: #2563eb;
  --color-primary-dark: #1e40af;
  --color-secondary: #10b981;
  --color-accent: #f59e0b;
  --color-text: #1f2937;
  --color-text-light: #6b7280;
  --color-bg: #ffffff;
  --color-bg-light: #f9fafb;
  --color-bg-dark: #111827;
  --color-border: #e5e7eb;
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
  --radius-sm: 0.375rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;
  --spacing-xs: 0.5rem;
  --spacing-sm: 1rem;
  --spacing-md: 1.5rem;
  --spacing-lg: 2rem;
  --spacing-xl: 3rem;
  --spacing-2xl: 4rem;
  --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

* {
  box-sizing: border-box;
}

body {
  background-color: var(--color-bg-light);
  color: var(--color-text);
  font-family: 'Noto Sans JP', 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Helvetica Neue', Arial, sans-serif;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--spacing-md);
}

/* ============================================
   Navigation
   ============================================ */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  background-color: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(10px);
  box-shadow: var(--shadow-sm);
  z-index: 1000;
  transition: var(--transition);
}

.navbar--scrolled {
  box-shadow: var(--shadow-md);
}

.navbar__container {
  max-width: 1200px;
  margin: 0 auto;
  padding: var(--spacing-sm) var(--spacing-md);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.navbar__logo {
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--color-primary);
  letter-spacing: 0.05em;
}

.navbar__links {
  display: flex;
  gap: var(--spacing-lg);
}

.navbar__link {
  color: var(--color-text);
  text-decoration: none;
  font-weight: 500;
  font-size: 0.9375rem;
  transition: var(--transition);
  position: relative;
  padding: var(--spacing-xs) 0;
}

.navbar__link::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background-color: var(--color-primary);
  transition: var(--transition);
}

.navbar__link:hover {
  color: var(--color-primary);
}

.navbar__link:hover::after {
  width: 100%;
}

/* ============================================
   Hero Section
   ============================================ */
.hero {
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: white;
  padding: calc(80px + var(--spacing-2xl)) var(--spacing-md) var(--spacing-2xl);
  text-align: center;
  position: relative;
  overflow: hidden;
  min-height: 60vh;
  display: flex;
  align-items: center;
  justify-content: center;
}

.hero::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: url('data:image/svg+xml,<svg width="100" height="100" xmlns="http://www.w3.org/2000/svg"><defs><pattern id="grid" width="100" height="100" patternUnits="userSpaceOnUse"><path d="M 100 0 L 0 0 0 100" fill="none" stroke="rgba(255,255,255,0.1)" stroke-width="1"/></pattern></defs><rect width="100" height="100" fill="url(%23grid)"/></svg>');
  opacity: 0.3;
  animation: gridMove 20s linear infinite;
}

@keyframes gridMove {
  0% {
    transform: translate(0, 0);
  }
  100% {
    transform: translate(100px, 100px);
  }
}

.hero__container {
  max-width: 1200px;
  margin: 0 auto;
  position: relative;
  z-index: 1;
}

.hero__content {
  animation: fadeInUp 0.8s ease-out;
}

.hero__title {
  margin: 0;
  display: flex;
  flex-direction: column;
  gap: var(--spacing-sm);
}

.hero__name {
  font-size: clamp(2.5rem, 5vw, 4rem);
  font-weight: 700;
  letter-spacing: 0.02em;
  line-height: 1.2;
}

.hero__role {
  font-size: clamp(1rem, 2vw, 1.5rem);
  font-weight: 400;
  opacity: 0.9;
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

.hero__subtitle {
  margin-top: var(--spacing-lg);
  font-size: clamp(1rem, 1.5vw, 1.25rem);
  opacity: 0.95;
  max-width: 700px;
  margin-left: auto;
  margin-right: auto;
  font-weight: 300;
  letter-spacing: 0.02em;
  line-height: 1.7;
}

/* ============================================
   Section Styles
   ============================================ */
.section {
  padding: var(--spacing-2xl) 0;
}

.section__title {
  text-align: center;
  margin-bottom: var(--spacing-2xl);
  position: relative;
}

.section__title-text {
  display: inline-block;
  font-size: clamp(1.75rem, 3vw, 2.5rem);
  font-weight: 700;
  color: var(--color-text);
  position: relative;
  padding-bottom: var(--spacing-md);
}

.section__title-text::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 80px;
  height: 4px;
  background: linear-gradient(90deg, var(--color-primary), var(--color-secondary));
  border-radius: var(--radius-sm);
  animation: expandLine 0.8s ease-out;
}

@keyframes expandLine {
  from {
    width: 0;
  }
  to {
    width: 80px;
  }
}

/* ============================================
   About Section
   ============================================ */
.about {
  background-color: var(--color-bg);
  position: relative;
  overflow: hidden;
}

.about::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--color-border), transparent);
}

.about__content {
  display: grid;
  grid-template-columns: 1.5fr 1fr;
  gap: var(--spacing-2xl);
  align-items: start;
}

.about__main {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-2xl);
}

.about__text-block {
  position: relative;
  padding-left: calc(var(--spacing-xl) + 24px);
}

.about__icon-wrapper {
  position: absolute;
  left: 0;
  top: 0;
  width: 56px;
  height: 56px;
  background: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
  border-radius: var(--radius-lg);
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-size: 1.5rem;
  box-shadow: var(--shadow-md);
  transition: var(--transition);
}

.about__text-block:hover .about__icon-wrapper {
  transform: scale(1.1) rotate(5deg);
  box-shadow: var(--shadow-lg);
}

.about__heading {
  font-size: 1.75rem;
  font-weight: 700;
  color: var(--color-text);
  margin: 0 0 var(--spacing-md) 0;
  letter-spacing: -0.02em;
}

.about__description {
  font-size: 1.0625rem;
  line-height: 1.9;
  color: var(--color-text);
  margin: 0 0 var(--spacing-lg) 0;
  letter-spacing: 0.01em;
}

.tech-stack {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-md);
  margin-top: var(--spacing-lg);
}

.tech-stack__group {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-sm);
}

.tech-stack__label {
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--color-text-light);
  text-transform: uppercase;
  letter-spacing: 0.1em;
}

.tech-stack__tags {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-sm);
}

.tech-tag {
  display: inline-block;
  padding: var(--spacing-xs) var(--spacing-md);
  background: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
  color: white;
  font-size: 0.875rem;
  font-weight: 600;
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
  transition: var(--transition);
}

.tech-tag:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.about__side {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-lg);
  position: sticky;
  top: calc(80px + var(--spacing-md));
}

.about__card {
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  padding: var(--spacing-xl);
  transition: var(--transition);
  box-shadow: var(--shadow-sm);
  position: relative;
  overflow: hidden;
}

.about__card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: linear-gradient(90deg, var(--color-primary), var(--color-secondary));
  transform: scaleX(0);
  transition: var(--transition);
}

.about__card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-xl);
  border-color: var(--color-primary);
}

.about__card:hover::before {
  transform: scaleX(1);
}

.about__card--strength::before {
  background: linear-gradient(90deg, #f59e0b, #d97706);
}

.about__card--future::before {
  background: linear-gradient(90deg, #10b981, #059669);
}

.about__card-icon {
  width: 64px;
  height: 64px;
  background: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
  border-radius: var(--radius-lg);
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-size: 1.75rem;
  margin-bottom: var(--spacing-md);
  box-shadow: var(--shadow-md);
  transition: var(--transition);
}

.about__card:hover .about__card-icon {
  transform: scale(1.1) rotate(5deg);
}

.about__card--strength .about__card-icon {
  background: linear-gradient(135deg, #f59e0b, #d97706);
}

.about__card--future .about__card-icon {
  background: linear-gradient(135deg, #10b981, #059669);
}

.about__card-title {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--color-text);
  margin: 0 0 var(--spacing-md) 0;
  letter-spacing: -0.02em;
}

.about__card-text {
  font-size: 1rem;
  line-height: 1.8;
  color: var(--color-text);
  margin: 0;
  letter-spacing: 0.01em;
}

/* ============================================
   Skills Section
   ============================================ */
.skills {
  background-color: var(--color-bg-light);
}

.skills__category {
  margin-bottom: var(--spacing-2xl);
}

.skills__category:last-child {
  margin-bottom: 0;
}

.skills__category-title {
  font-size: 1.5rem;
  font-weight: 600;
  margin-bottom: var(--spacing-lg);
  color: var(--color-text);
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
}

.skills__category-title i {
  color: var(--color-primary);
  font-size: 1.25rem;
}

.skills__grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: var(--spacing-md);
}

.skill-tag {
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: var(--spacing-md) var(--spacing-lg);
  display: flex;
  justify-content: space-between;
  align-items: center;
  transition: var(--transition);
  box-shadow: var(--shadow-sm);
  position: relative;
  overflow: hidden;
  cursor: default;
}

.skill-tag::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 4px;
  height: 100%;
  background-color: var(--color-primary);
  transform: scaleY(0);
  transition: var(--transition);
}

.skill-tag:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
  border-color: var(--color-primary);
}

.skill-tag:hover::before {
  transform: scaleY(1);
}

.skill-tag--a::before {
  background-color: #10b981;
}

.skill-tag--b::before {
  background-color: #f59e0b;
}

.skill-tag--c::before {
  background-color: #6b7280;
}

.skill-tag__name {
  font-weight: 500;
  color: var(--color-text);
  font-size: 0.9375rem;
}

.skill-tag__level {
  background: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
  color: white;
  font-size: 0.75rem;
  font-weight: 700;
  padding: 0.25rem 0.5rem;
  border-radius: var(--radius-sm);
  min-width: 28px;
  text-align: center;
}

.skill-tag--a .skill-tag__level {
  background: linear-gradient(135deg, #10b981, #059669);
}

.skill-tag--b .skill-tag__level {
  background: linear-gradient(135deg, #f59e0b, #d97706);
}

.skill-tag--c .skill-tag__level {
  background: linear-gradient(135deg, #6b7280, #4b5563);
}

/* ============================================
   Process Section
   ============================================ */
.process {
  background-color: var(--color-bg);
}

.process__grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: var(--spacing-lg);
}

.process-card {
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--spacing-xl);
  text-align: center;
  transition: var(--transition);
  box-shadow: var(--shadow-sm);
  position: relative;
  overflow: hidden;
}

.process-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: linear-gradient(90deg, var(--color-primary), var(--color-secondary));
  transform: scaleX(0);
  transition: var(--transition);
}

.process-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-xl);
  border-color: var(--color-primary);
}

.process-card:hover::before {
  transform: scaleX(1);
}

.process-card--a::before {
  background: linear-gradient(90deg, #10b981, #059669);
}

.process-card--b::before {
  background: linear-gradient(90deg, #f59e0b, #d97706);
}

.process-card__icon {
  width: 64px;
  height: 64px;
  background: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-size: 1.75rem;
  margin: 0 auto var(--spacing-md);
  transition: var(--transition);
}

.process-card:hover .process-card__icon {
  transform: scale(1.1) rotate(5deg);
}

.process-card--a .process-card__icon {
  background: linear-gradient(135deg, #10b981, #059669);
}

.process-card--b .process-card__icon {
  background: linear-gradient(135deg, #f59e0b, #d97706);
}

.process-card__title {
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--color-text);
  margin: 0 0 var(--spacing-md) 0;
  line-height: 1.4;
}

.process-card__level {
  display: inline-block;
  background: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
  color: white;
  font-size: 1.25rem;
  font-weight: 700;
  padding: var(--spacing-xs) var(--spacing-md);
  border-radius: var(--radius-md);
  min-width: 48px;
}

.process-card--a .process-card__level {
  background: linear-gradient(135deg, #10b981, #059669);
}

.process-card--b .process-card__level {
  background: linear-gradient(135deg, #f59e0b, #d97706);
}

/* ============================================
   Footer
   ============================================ */
.footer {
  background-color: var(--color-bg-dark);
  color: white;
  padding: var(--spacing-xl) 0;
  margin-top: var(--spacing-2xl);
}

.footer__content {
  text-align: center;
}

.footer__social {
  display: flex;
  justify-content: center;
  gap: var(--spacing-md);
  margin-bottom: var(--spacing-md);
}

.footer__social-link {
  width: 44px;
  height: 44px;
  background-color: rgba(255, 255, 255, 0.1);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-size: 1.25rem;
  transition: var(--transition);
  text-decoration: none;
}

.footer__social-link:hover {
  background-color: var(--color-primary);
  transform: translateY(-3px);
  box-shadow: var(--shadow-lg);
}

.footer__copyright {
  color: rgba(255, 255, 255, 0.7);
  font-size: 0.875rem;
  margin: 0;
}

/* ============================================
   Animations
   ============================================ */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* ============================================
   Responsive Design
   ============================================ */
@media (max-width: 768px) {
  .navbar__links {
    gap: var(--spacing-sm);
  }

  .navbar__link {
    font-size: 0.875rem;
  }

  .hero {
    padding: calc(70px + var(--spacing-xl)) var(--spacing-md) var(--spacing-xl);
  }

  .section {
    padding: var(--spacing-xl) 0;
  }

  .about__content {
    grid-template-columns: 1fr;
    gap: var(--spacing-xl);
  }

  .about__side {
    position: static;
  }

  .about__text-block {
    padding-left: calc(var(--spacing-lg) + 24px);
  }

  .about__icon-wrapper {
    width: 48px;
    height: 48px;
    font-size: 1.25rem;
  }

  .about__heading {
    font-size: 1.5rem;
  }

  .about__description {
    font-size: 1rem;
  }

  .about__card {
    padding: var(--spacing-lg);
  }

  .process__grid {
    grid-template-columns: 1fr;
  }

  .skills__grid {
    grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
    gap: var(--spacing-sm);
  }

  .process-card {
    padding: var(--spacing-lg);
  }
}

@media (max-width: 480px) {
  .navbar__container {
    flex-direction: column;
    gap: var(--spacing-sm);
  }

  .navbar__links {
    flex-wrap: wrap;
    justify-content: center;
  }

  .hero {
    min-height: 50vh;
    padding: calc(100px + var(--spacing-lg)) var(--spacing-md) var(--spacing-lg);
  }

  .about__text-block {
    padding-left: calc(var(--spacing-md) + 20px);
  }

  .about__icon-wrapper {
    width: 40px;
    height: 40px;
    font-size: 1.125rem;
  }

  .about__heading {
    font-size: 1.25rem;
  }

  .about__description {
    font-size: 0.9375rem;
  }

  .skills__grid {
    grid-template-columns: 1fr;
  }

  .tech-stack__tags {
    gap: var(--spacing-xs);
  }

  .tech-tag {
    font-size: 0.8125rem;
    padding: 0.375rem var(--spacing-sm);
  }
}